Honorable Mention: International Architecture Awards 2025
A Modern Sponge City Inspired by Ancient Wisdom: Sanya Dong’an Wetland Park | Sanya, China | 2021

Architects: Turenscape
Design Team: Kongjian Yu, Zhang Yu, Yu Wenyu, Baizhen, Zheng Junyan, Wu Fan, Song Jia, Wang Fang, Wang Jiao, Dong Tianyi, Bian Yaguang, Wang Yufei, Li Fei, Zhou Zhou, and Li Jingbai
General Contractor: Sanya City Government
Client: Sanya City Government
Photographers: Turenscape

1. Project statement

Under the influence of a monsoon climate and global climate change, the city of Sanya suffered severe flooding and urban inundation. Together with other water-related problems such as pollution and habitat loss, this made the city a key proving ground for China’s sponge city campaign, launched in 2014. The project was built quickly, at low cost and in a manner replicable at large scale and has become one of the most significant demonstration and multi-functional projects of the nationwide sponge city effort. 

2. Site and challenges  

168 acres in size in central Sanya City in China’s Hainan Island, the site was a wetland that had been filled with urban debris. The water was polluted and the wetland was degraded, which caused severe urban inundation in the surrounding communities, and resulted in foul odors and constant flooding. The scale of landscape transformation required was large, the timeline was short and the budget was limited, yet the practices demonstrated in this project needed to be widely replicable.

3. Design strategies

Three strategies were used to transform the site:

3.1 “Ecopuncture” based on a systematic hydrologic analysis
Envisioning the project as an integral part of the green infrastructure of a water-resilient city, the park was carefully planned after a systematic hydrological analysis of the entire metropolitan region that calls for more space for water and integrates wetlands, ponds, parks and coastal habitats into a holistic sponge system. 

3.2 Simple and inexpensive solutions 
Inspired by the ancient farm-building techniques of cut-and-fill used in the Pearl River Delta area in China, the landscape architect employed three types of earthwork approaches to quickly transform the site into a water-resilient landscape. 

At the periphery, the pond-and-dyke system was designed to retain and cleanse urban runoff from the surrounding communities. 
At the northeast edge, where the elevation drop is significant, terraces are created to stabilize the slope of the edge and catch the storm water runoff from upstream urban areas.

In the center, an island system was designed to create a lake scattered with islands. On each island, a banyan tree was planted; its dense root system will remove excess nutrients in the water, and the trees will eventually create a forest over the lake and cool off the lake.
    
3.3 Multiply and integrate the space to amplify eco-services
The design has created three superimposed layers of landscape: at the bottom, the lake, which function as a sponge to retain and cleanse storm water; in the middle, the vegetation and banyan forest, which become refuges for birds and other wild animals; and at the top, the skywalks over the tree canopy, which connect the surrounding communities and provide pleasant recreational spaces.

4. Conclusion
The park was built in one year and at a comparatively low cost. The eco-services the park provides are significant in that it not only solved the water-associated problems of the surrounding communities, it also become a great refuge for native biodiversity that attracts bird watchers and photographers. It is ranked as one of the most popular parks by residents and attracts thousands of visitors every day. It has been a catalyst for urban redevelopment, and the property value increased 300% in two years after the project was built.